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HP Recommended
HP Workstation Z820
Microsoft Windows 10 (64-bit)


I have  Z820 that currently run Windows 10 and the spec are:

Xeon CPU E5-2620 v2

128Gb Ram and quadro K6000.

I am using that workstation for CAD/CAM working. as far as I know the CAM software (mastercam/hypermill) does not support multi core CPU. and now its is slow when software do the calculator. After talk with hypermill they told me the CPU 2.1Ghz was too low.

Can I upgrade both CPU? I have read on the website and that Z820 support intel Xeon E5-2643 v2, E5-2637 v2, E5-2667 v2.

which one is better?

Also think about upgrade SSD to M2.

I need the advise

Thank you


HP Recommended

the fastest SSD that works in the z820 is the HP Turbo Z card (not the turbo Z G2)


the turbo z card uses a Samsund SM951 AHCI/SATA SSD, on a PCI-e card that uses x4 pci-e lanes . this is the fastest booting SSD available for the z820 ( you can also use any "SATA" based SSD as a boot drive,  but not a nvme ssd if you want to boot from it


nvme ssd's can only be used as "data"  (non booting drives) on the z820


for your work usage, a cpu with higher mhz vs more cores seems to be what you want


check the HP quickspecs for hp's approved cpu list




hp specs the upgraded 1150 watt supply when running two 130 watt cpu's and a high end video card. if using only one cpu, and just four sticks ram and one mech drive, you might be able to use the stock 850 watt supply but this is a non hp approved configuration


note that 130 watt cpu's require the upgraded heatsinks, and the 150 watt cpu's require the water cooling kit

HP Recommended



It's all about single-threaded performance: The fundamental performance deficit of the z820 is the CPU single-threaded performance, that is, the performance of the fastest single core in the processor which is in turn influenced by the architecture of the processor.  The  Xeon E5-2620 v2 6-Core@2.1/2.6GHz is more of a server processor, designed for continuous 100% utilization running.  The Passmark Single-Thread Mark for the  E5-2620 v2 averages 1282.  For comparison,  the highest average STM is 2907 for the Intel Core i9-9900KF and in the office z620 CAD workstation, the E5-1680 v2, 8-core running at 4.3GHz on all cores makes an STM of 2364.  I would like this to be 2500+.


CPU Suggestions:  My suggestion is that the z820 be run on a single Xeon E5-1660 v2, either at the stock 3.7 / 4.0GHz or, employing the z820 liquid cooler, overclock to 4.3GHz using a previous version of Intel Extreme Tuning Utility. [Note: Xeon E5-16XX are strictly single processor application and E5-26XX may be run singly or in pairs]. 


Alternative: Xeon E5-1650 v2. The office second workstation is a z420, liquid cooled, running a Xeon E5-1650 v2 (purchased three weeks ago for $90)  at 4.3GHz on all cores and the STM is 2385. 


M.2 drive: I've used M.2 in the z620 for more than two years, adding a Samsung 970EVO 500GB NVMe a few months ago as a data drive.  The zX20 series can not use NVMe as boot drives without some quite technical measures or special "legacy boot" models such as the Samsung 950 Pro. In my use, there is not a  noticeable advantage. I've timed booting and large file opening and the difference is only a few seconds. In some heavier image processing, including rendering, the data swapping stays in the RAM anyway and the two systems have 64GB and 32GB.


Alternative for consideration:   Be aware that there is some performance deficit in dual CPU systems as the QPI link between the two sockets presents a parity check to sync the two processors. To demonstrate, the highest clock speed Xeon E5 v2 is the E5-2687W v2 with an average STM of 2041. If the system is permanently for CAD /CAM, consider changing to a z420 or z620 with a Xeon E5-1660 v2,  z420 liquid cooling, running at 4.1 to 4,3 GHZ using Intel Extreme tuning Utility, 32GB or 64GB of HP-branded PC3-14900E ECC unbuffered or PC3-14900R registered.


Yes, some amount of trouble, but the value of a complete running z820 with dual E5's should quite easily surpass  the cost.


For example:








Continuing on this theme, the Quadro K6000 is quite valuable due to it's 12GB of VRAM.  If extremely large files are not in play in the subject system consider converting that value (quite equally) to a Quadro P4000 8GB..


Quadro K6000  Passmark average 3D = 7433

Quadro P4000  Passmark average 3D =10549





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